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very high head pressure with very low suction pressure

went to customer home check on r22 heat pump cut out ,the pressure on high side is 400 lbs,and low side is 30 lbs in cooling mode,and it run 3mins and cut off each time u turn it on,and running in heat mode the pressure is normal,but still cut off in few mins,check the line voltage is normal,condenser coil is clean,indoor coil in new with tev,and running in heat or cool mode the suction line get correct temp(hot and cold real fast),he already have two tech come look at it,cant find out what is wrong,i think is new indoor coil restriction,or even system have more then one problemmaybe air in the system,but customer said it is new cant be!what do ur thinks?thanks

High head - low suction

I'm new here, but a seasoned tech. To me I would be looking at your new coil. If the sensing bulb is not placed correctly, it will royally screw things up. Second, it is not uncommon to have a new, defective TXV. I have ran into it several times. Check the liquid line temp before and after the metering device. Check your delta "T" at the indoor coil. Make sure the house is not lacking return air(Very common in old houses), make sure the customers furniture is not restricting the return air grills upstairs. I would be checking different parts of the system with your thermometer. Ensure the fan is set at the proper cfm. In my opinion. it's always best to start at the basics. Hope this helps.

Sound like you have a restriction in the system. Verify your airflow and check the TXV if used with the new coil if not piston maybe clogged, check temp across filter drier, look for an unintentional kink in lineset after the new coil was installed.

This is a classic sign of a partial restriction that we argue about here around once a year. It goes against what we're taught but even with the proper charge it will cause extremely high head pressure. It obviously has to be down stream from wherever you're reading the high pressure. If you're reading is on the liquid line then the indoor coil would have nothing to do with it. The most common place would be the metering device or screen at the outside unit but as suggested it could also be a plugged dryer but that's pretty unlikely.

went to customer home check on r22 heat pump cut out ,the pressure on high side is 400 lbs,and low side is 30 lbs in cooling mode,and it run 3mins and cut off each time u turn it on,and running in heat mode the pressure is normal,but still cut off in few mins,check the line voltage is normal,condenser coil is clean,indoor coil in new with tev,and running in heat or cool mode the suction line get correct temp(hot and cold real fast),he already have two tech come look at it,cant find out what is wrong,i think is new indoor coil restriction,or even system have more then one problemmaybe air in the system,but customer said it is new cant be!what do ur thinks?thanks

A cold suction line (low superheat) with low suction pressure is a symptom of low evaporator air. A liquid restriction would result high superheat (warm suction line). The high head probably due to the other guys overcharging, trying to get the suction pressure up.

But the low air problem would result in high head pressure in the heat cycle.

If the contactor is actually dropping out, I would guess a hi/lo pressure limit opening.

This is a classic sign of a partial restriction that we argue about here around once a year. It goes against what we're taught but even with the proper charge it will cause extremely high head pressure. It obviously has to be down stream from wherever you're reading the high pressure. If you're reading is on the liquid line then the indoor coil would have nothing to do with it. The most common place would be the metering device or screen at the outside unit but as suggested it could also be a plugged dryer but that's pretty unlikely.

My bad,

I read the OP wrong, I thought it was fine in cooling but high head in heating so disregard this post. I'll have to read it over again.
I'd still be looking at a restriction with those pressures but a little more info is needed about both cycles.

3 mins of runtime will not allow you to get an accurate superheat/subcooling reading so giving a solution to first correct the problem (3mins then cut off) is more than just guessing, then checking superheat/subcooling to specs to properly charge the system. Pressure alone in this instance is more than enough info. Come on now!!!

any body think maybe compressor trip cause it have running with low freon for long time,maybe mechanicaly falier in compressor over heat and trip?that is one more thing i have to check amp draw from compressor,cause i am looking at the liquid line restruction and high and low pressure to long,lol,